Electric ranges are commonly used in a great many homes in the United States and abroad. The typical electric range includes a stove top having four or more coiled electrical resistance heating elements, commonly known as burners or burner elements. During use, cooking vessels such as pots or pans are placed directly on the coiled burner element. The burner element is then set to the desired temperature, and the cooking process begun. Although generally effective, this standard configuration is not without its disadvantages. More specifically, significant heat is lost through contact resistance between the burner element and cooking vessel.
As a practical example of this type of heat loss, a kettle about to boil can be induced into boiling by actively pressing the kettle downwardly onto the burner element. While thus engaged, the kettle boils. When released, the boiling action stops. It can be seen that pressing the kettle downwardly forces it into tight engagement with the burner element overcoming the contact resistance. This contact resistance arises as a result of incomplete contact between the burner element and the cooking vessel. More specifically, air pockets form in the areas of incomplete contact. These air pockets act as effective thermal insulators, preventing efficient conduction of heat. The practical disadvantage of this contact resistance is greater use of energy through the requirements of longer cooking times and cooking at higher temperatures to achieve the desired cooking result.
U.S. Pat. No. 1,386,303 to Armstrong discloses a heat conducting pad placed on a burner element of a stove. The pad is filled with metallic pieces which are about the size of ordinary shot. In use, the weight of the cooking vessel forces some degree of conformity between the vessel and burner, increasing heat transfer somewhat. Although the pad generally conforms to the burner element and cooking vessel, effective heat transfer is limited to the paths defined by physical contact of the metallic shot. Additionally, because the pad is not homogeneous, it necessarily contains air. The air pockets thus contained form thermal insulators, thereby reducing the effectiveness of the heat conducting pad.
U.S. Pat. 3,845,273 to Hurko discloses a composite metal burner unit having a smooth upper surface. Although this device may increase heat transfer somewhat, the upper plate is not flexible so as to conform to the contours of the cooking vessel. Additionally, the device must be built into the stovetop and is not easily retrofitted onto units already in use.
A need exists, therefore, for a flexible heat transfer pad designed to be installed on the coiled burner element of a stove. Such a device would be flexible to conform to the contours of the burner element and the cooking vessel during use, thereby greatly increasing overall heat transfer. Such a device would be simple, self-contained, economical and easily installed on stoves already in use.